Polyisocyanatoimido compositions and imide group containing polymers prepared therefrom

ABSTRACT

A coating or molding composition including a polyisocyanate, an unsaturated imide and an olefinically unsaturated comonomer copolymerizable with the unsaturated imide, and having a ratio of total isocyanate functions to total polymerizable double bonds in the imide in the range of from 0.3 to 15, is addition polymerized to hard, imide group containing polymers characterized by the recurring unit: ##STR1## Coatings and shaped articles formed from such polymers are hard, tough, thermally stable, solvent resistant and are good insulators.

This is a division, of application Ser. No. 865,210, filed Dec. 28, 1977now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to novel imide group containing polymers,compositions for the preparation thereof, and uses therefor.

2. Summary of the Invention

The novel polymers according to the invention are characterized by thefact that same are prepared by reaction between or among:

(A) A compound comprising an isocyanate functional group selected fromthe group consisting of polyisocyanates, and mixtures of polyisocyanatesand monoisocyanates; and

(B) One or more imides selected from the group consisting of:

(i) Monoimides of the formula: ##STR2## wherein D represents ##STR3## inwhich Y is H, CH₃ or Cl, and Z is either 0, 1 or 2, and R₁ represents ahydrogen atom or a monovalent aliphatic, cycloaliphatic or aromatichydrocarbon radical containing up to 20 carbon atoms; and

(ii) Polyimides of the formula: ##STR4## wherein D is as above, n is annumber ranging from 2 to 5 and R₂ is a radical having the valence n,such radical being either wholly hydrocarbon or including heteroatom(s),which heteroatom(s) may either comprise a component heterocyclic moietyor may serve as a mere bridge or linkage in said radical i.e., such R₂radical being selected from the group consisting of a wholly hydrocarbonradical, a heteroatom interrupted hydrocarbon radical, a heterocycleradical, and a heterocycle containing hydrocarbon radical, with thereagents (A) and (B) being utilized in quantities such that, if n₁designates the number of NCO groups provided by the compound bearing theisocyanate groups and n₂ designates the number of double bonds suppliedby the imide, the ratio r=n₁ /n₂ is between 0.3 and 15.

DETAILED DESCRIPTION OF THE INVENTION

It is intended herein that the term polyisocyanate designate allcompounds containing at least two NCO groups. Therefore, both a lowmolecular weight polyisocyanate (polyisocyanate monomer) or amacropolyisocyanate (polyisocyanate prepolymer) may be used. Thepolyisocyanate monomers are represented by the following formula:

    R.sub.3 -NCO).sub.m                                        [III]

in which m is an number of from 2 to 5 and, preferably, either 2 or 3,R₃ represents a radical with the valence m and is an aliphatic,cycloaliphatic or aromatic radical having up to 50 carbon atoms. The R₃radical, more particularly, can be a straight or branched chainaliphatic radical having up to 12 carbon atoms, advantageously analkylene radical, a cycloaliphatic radical having 5 to 6 ring carbonatoms, a monocyclic aromatic radical, desirably having from 6 to 10carbons, e.g., phenylene or naphthalene, a ##STR5## radical where p=1, 2or 3, a polycyclic aromatic radical as defined above, the individualrings of which may either be condensed or joined by a simple valencebond, or linked by an atom or group such as --O--, --S--, --SO₂ -- or byalkylene radical containing 1 to 4 carbon atoms, and wherein the variousaromatic nuclei may be substituted with one or more halogen atoms, orwith one or more alkyl radicals having 1 to 4 carbon atoms, or with amethoxy group.

As specific examples of the monomeric polyisocyanates of Formula III,the following are noted as representative:

Toluene-2,4-diisocyanate;

Mixtures of toluene-2,4-diisocyanate and toluene-2,6-diisocyanate;

Bis(4-isocyanatophenyl) methane;

Paraphenylene diisocyanate;

Metaphenylene diisocyanate;

1,5-diisocyanatonaphtalene

Tris(4-isocyanatophenyl) methane;

2,4-Diisocyanato-chlorobenzene;

Bis(4-isocyanatophenyl) ether;

1,6-Diisocyanatohexane;

3-3'-Dimethyl-4,4'-diisocyanato-biphenyl;

Bis(4-isocyanatocyclohexyl) methane;

Bis(3-methyl-4-isocyanatophenyl) methane;

Bis(4-isocyanatophenyl) propane;

4,4'-Diisocyanato-3,3'-dichloro-diphenyl; and

Polyisocyanates of the formula: ##STR6## where w is a number rangingfrom 0.1 to 4.

The polyisocyanate can also be a polyisocyanate prepolymer which can berepresented by the formula:

    OCN--Σ--NCO                                          [IV]

in which the nucleus --Σ--_(q) designates a polymer chain and the symbolq the number of repeating units constituting the polymer chain, having avalue such that the molecular weight of the polyisocyanate of Formula IVcan range up to 12,000.

The prepolymer of Formula IV may specifically be a macrodiisocyanate ofthe formulae: ##STR7## resulting from the reaction of a molar excess ofa diisocyanate of the formula OCN--R₃ --NCO with a polymer containing atleast two reactive hydroxyl or amino groups. The dihydroxylated polymermay be of a varied nature. Thus, as is now well known, it may consist ofhydroxylated polybutadiene, castor oil, hydroxylated epoxy resins. Itmay also consist, and this embodiment represents a type of preferredpolymer according to the invention, of a polyester or a polyether. Thepolyester is typically prepared from a dicarboxylic acid and a diol,using an amount of the reagents such that the OH/COOH ratio is greaterthan 1 and preferentially between 1.1 and 2.

As examples of dicarboxylic acids, the following are mentioned as beingpreferred: aliphatic acids such as succinic, glutaric, adipic, pimelic,suberic, azelaic, sebacic, maleic, fumaric, methyliminodiacetic, anddimethyl-amino-3-hexanedioic, the cycloalkane dicarboxylic acids, suchas cyclohexane-1,4-dicarboxylic acid,3-dimethylaminocyclopentane-1,2-dicarboxylic acid, the aromatic diacids,such as the phthalic acids and naphthalene-1,5-dicarboxylic acid, thepyrimidine dicarboxylic acids or imidazole dicarboxylic acid.

Exemplary of the diols, there are mentioned: 1,2-ethanediol, the 1,2 and1,3 propanediols, the 1,2-, 2,3-, 1,3- and 1,4-butanediols,1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol,2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, butanediol,butynediol, ethyldiethanolamine. The α,ω-hydroxylated polyethers, suchas the poly(oxyalkylene) glycols, noted hereunder as examples of thepolyethers, may also be used.

Specifically referring to the conditions under which the diacid/diolcondensation may take place, the work Polyesters (Pergamon Press, 1965)by Korshak & Vinogradova, is incorporated by reference.

The α,ω-dihydroxylated polyether may be selected from among thepoly(oxyalkylene) glycols, such as the poly(oxyethylene) glycols, thepoly(oxypropylene) glycols, copolymers withpoly(oxyethylene)-poly(oxypropylene) blocks, the poly(oxytetramethylene)glycols obtained by the polymerization of terahydrofuran, thepoly(oxybutadiene) glycols obtained from 1,2-epoxy and/or 2,3-epoxybutane, copolymers with poly(oxyethylene)-poly(oxybutylene) and possiblypoly(oxypropylene) blocks. Similarly, polyethers containing nitrogen,prepared from ethylene oxide, propylene oxide and/or butylene oxide anda nitrogen compound such as ethylenediamine, benzene sulfonamide,N-methyldiethanolamine, amino-2 ethylethanolamine, may also be used aspolyethers.

Naturally, the polyisocyanate may be prepared from a mixture of morethan one α,ω-hydroxylated polymers, which may be of similar or differentchemical nature.

Also, as indicated above, an α,ω-diamine polymer may be used in place ofthe α,ω-hydroxylated polymer. Such polymers may be obtained, forexample, by the reaction of a dicarboxylic diacid such as thosementioned above, with a molar excess of diamine.

The diamines themselves may be aliphatic, such as, for example,ethylenediamine, hexamethylenediamine, cycloaliphatic, such as, forexample, 1,4-diaminocyclohexane, or aromatic, such as for example,paraphenylendiamine, bis(4-aminophenyl)methane, bis(4-aminophenyl)ether,paraxylylenediamine. Moreover, polybutadiene or polyisoprene bearingpendant NH₂ groups or, as aforesaid, macrodiamines obtained by thereaction of an excess of diamine with an epoxy resin may also be used asthe amine polymer. Such macrodiamines are described, for example, inFrench Pat. No. 2,259,860 [corresponding to U.S. Pat. No. 3,978,152]. Apolyamide-imide having an NCO terminal group, obtained either by thedirect reaction of a molar excess of diisocyanate with trimelliticanhydride, or by the reaction of a diisocyanate with a polyamide-imidehaving a terminal NH₂ prepared by the reaction of trimellitic anhydridewith a molar excess of diamine, may also be used. It is apparent fromthe immediately aforesaid that other types of polymers which react withisocyanates may be used, for examples, the polyesteramides themselveswell known to the art.

To prepare the polyisocyanate prepolymer from a hydroxyl or aminepolymer, the reagents (diisocyanate and polymer) are used in amountssuch that the ratio of the number of NCO groups/number of OH or NH₂groups is greater than 1, preferably between 1.1 and 10. Naturally, amixture of diisocyanates may be used.

For the sake of simplicity only, the preparation of the polyisocyanateprepolymer has been above described solely from difunctional reagents.It is nonetheless apparent, by using a hydroxyl polymer containing morethan two hydroxyl groups, for example, by utilizing a polyol in therecipe, to prepare a polyisocyanate prepolymer containing more than twoNCO groups per mole (on the average). As examples of such polyols,trimethylol propane, pentaerythritol, saccharose, sorbitol, arementioned.

The conditions of the reaction between the diisocyanate and the hydroxylpolymer are described, for example, in Polyurethane Chemistry andTechnology of J. H. Saunders & K. C. Frisch, Part I, 1962.

As heretofore indicated, the invention also contemplates use of apolyisocyanate or a mixture of polyisocyanates, or a mixture of suchproducts with one or more monoisocyanates.

Such monoisocyanates are represented by the formula

    G--NCO                                                     [VII]

wherein the symbol G is a saturated or unsaturated, linear or branchedchain aliphatic radical, having up to 8 carbon atoms, typically an alkylradical, a cycloalkyl radical with 5 or 6 carbon atoms, a phenylradical, an alkylphenyl or phenyl alkyl radical with up to 12 carbonatoms; the various radicals, moreover, may be substituted by one or twochlorine atoms or a methoxy group. Exemplary of such isocyanates ofFormula VII, isopropylisocyanate, n-propylisocyanate,tertiobutylisocyanate, propenylisocyanate, chlorophenylisocyanate,dichlorophenylisocyanate, benzylisocyanate, cyclohexylisocyanate,p-methoxyphenylisocyanate, are mentioned.

If a monoisocyanate indeed be used, the quantity of NCO groups suppliedby such single function compound should not represent, preferably, morethan 30% of the total number of NCO groups supplied by themono+polyisocyanate mixture.

The second essential component in the preparation of the polymersaccording to the invention is a compound with an imide group. Thiscompound may be a monoimide (I), a polyimide containing up to 5 imidegroups (II), or a mixture of the compounds I and II.

In Formula I, the symbol R₁, if it does not represent hydrogen, mayspecifically represent a linear or branched chain alkyl or alkenylradical containing up to 20 carbon atoms, a cycloalkyl radicalcontaining 5 or 6 carbon atoms in the ring, a mono- or bicyclic arylradical or aralkyl radical containing up to 20 carbon atoms, one of theradicals: ##STR8## a monovalent radical consisting of a phenyl radicaland at least one phenylene radical joined together by a simple valencebond or by an atom or an inert linking group such as: --O--, --S--, analkylene radical with 1 to 3 carbon atoms, --CO--, --SO₂ --, --NR₄ --,--N═N--, --CONH--, --COO--, where R₄ represents H, CH₃, phenyl orcyclohexyl. In addition, these different radicals may be substituted byone or more atoms, radicals or groups, such as F, Cl, CH₃, OCH₃, OC₂ H₅,OH, NO₂, --COOH, --NHCOCH₃, and ##STR9##

As specific examples of monoimides of Formula I, there are mentionedmaleimide, N-phenylmaleimide, N-methylphenylmaleimide,N-phenylchloromaleimide, N-p-chlorophenylmaleimide,N-p-methoxyphenylmaleimide, N-p-methylphenylmaleimide,N-p-nitrophenylmaleimide, N-p-phenoxyphenylmaleimide,N-p-phenylcarbonylphenylmaleimide, maleimido-1-acetoxysuccinimido-4benzene, maleimido-4-acetoxysuccinimido-4'-diphenylmethane,maleimido-4-acetoxysuccinimido-4'diphenylether,maleimido-4-acetamido-4'-diphenylether,maleimido-2-acetamido-6-pyridine,maleimido-4-acetamido-4'-diphenylmethane, N-methylmaleimide,N-ethylmaleimide, N-vinylmaleimide, N-allylmaleimide,N-cyclohexylmaleimide, N-decylmaleimide.

These monoimides can be prepared by the methods described, for example,in U.S. Pat. Nos. 2,444,536 and 3,717,615 or the German patentapplication (DOS) No. 2,354,654 [corresponding to U.S. Pat. No.3,875,113].

In Formula II, the symbol R₂ may specifically represent a divalentradical selected from among the following:

An alkylene radical, linear or branched, containing up to 13 carbonatoms;

A cyclohexylene or cyclopentylene radical;

A phenylene or naphtylene radical;

One of the following radicals; ##STR10## where s is equal to 1, 2 or 3;

A radical containing two phenylene or cyclohexylene radicals joined toeach other by a simple valence bond or by a linking atom or inert group,such as --O--, --S--, an alkylene group having 1 to 3 carbon atoms,--CO--, --SO₂ --, --NR₅ --, --N═N--, --CONH--, --COO--, --P(O)R₅,--CONH--X--NHCO--, ##STR11## where R₅ represents a hydrogen atom, analkyl radical having 1 to 4 carbon atoms, phenyl or cyclohexyl and Xrepresents an alkylene radical having up to 13 carbon atoms.

As specific examples of such bis-imides the following may be cited:

N,N'-Ethylene-bis-maleimide;

N,N'-Metaphenylene-bis-maleimide;

N,N'-hexamethylene-bis-maleimide;

N,N'-Paraphenylene-bis-maleimide;

N,N'-4,4'-Biphenylene-bis-maleimide;

N,N'-4,4'-Diphenylmethane-bis-maleimide;

N,N'-4,4'-Diphenylmethane-bis-tetrahydrophthalimide;

N,N'-4,4'-Diphenylether-bis-maleimide;

N,N'-4,4'-Diphenylthio-bis-maleimide;

N,N'-4,4'-Diphenylsulfone-bis-maleimide;

N,N'-4,4'-Dicyclohexylmethane-bis-maleimide;

N,N'-α,α'-4,4'-Dimethylene cyclohexane-bis-maleimide;

N,N'-Paraxylylene-bis-maleimide;

N,N'-4,4'-Diphenyl-1,1-cyclohexane-bis-maleimide;

N,N'-4,4'-Diphenylmethane-bis-citraconimide;

N,N'-4,4'-Diphenylether-bis-endomethylene tetrahydrophthalimide;

N,N'-4,4'-Diphenylmethane-bis-chloromaleimide;

N,N'-4,4'-Diphenyl-1,1-propane-bis-maleimide;

N,N'-4,4'-Triphenyl-1,1,1-ethane-bis-maleimide;

N,N'-4,4'-Triphenylmethane-bis-maleimide;

N,N'-3,5-Triazole-1,2,4-bis-maleimide;

N,N'-Dodecamethylene-bis-maleimide;

N,N'-Trimethyl-2,2,4-hexamethylene-bis-maleimide;

Bis(maleimido-2-ethoxy)-1,2-ethane;

Bis(maleimido-3-propoxy)-1,3-propane;

N,N'-4,4'-Benzophenone-bis-maleimide;

N,N'-Pyridinediyl-2,6-bis-maleimide;

N,N'-Naphthylene-1,5-bis-maleimide;

N,N'-Cyclohexylene-1,4-bis-maleimide;

N,N'-Methyl-5-phenylene-1,3-bis-maleimide;

N,N'-Methoxy-5-phenylene-1,3-bis-maleimide.

These bis-imides may be prepared by the methods described in U.S. Pat.No. 3,018,290 and British Patent Specification No. 1,137,592.

The symbol R₂ represents a radical containing up to 50 carbon atoms andcarrying 3 to 5 free valences, and wherein said radical may comprise anaphthalenic, pyridinic or triazinic nucleus, or a benzene nucleus thatmay be substituted by one to three methyl groups, or by a plurality ofbenzene nuclei joined together by a linking atom or an inert group whichmay be one of those indicated above, or ##STR12##

As examples of polyimides of this type, products with the followingformulae are noted: ##STR13## in which D is as above, y is a number from0.1 to 4, and R₆ is a divalent hydrocarbon radical having 1 to 8 carbonatoms, derived from an aldehyde or a ketone having the general formula:

    O═R.sub.6

in which the oxygen atom is bonded to a carbon atom of the radical R₆.

As hereinbefore mentioned, the ratio ##EQU1## is between 0.3 and 15.

The choice of a given definite value between these aforesaid extremelimits of r indicates to those skilled in the art, on one hand, thenature of the reactants involved, particularly their functionality and,on the other hand, the degree of reticulation desired for the polymersresulting from the reaction. The value of the ratio r is preferably from0.5 to 10.

The reaction between the polyisocyanate (A) and the imide (B) consistsessentially of the addition of the NCO group to one of the sites ofcarbon-to-carbon unsaturation in the imide, resulting in the formationof the group: ##STR14##

The reaction typically is conducted in the presence of an isocyanatepolymerization catalyst. Exemplary of such catalysts, desirably thetertiary amines, are tris-dimethylaminomethyl-2,4,6-phenol,benzyl-2-pyridine, N-methyl-morpholine, triethylamine,bis(dimethylamino)-1,3-butane, N,N'-diethylcyclohexylamine, thecarboxylates, for example, potassium, sodium or calcium acetate, sodiumnaphthenate, and the alkoxides, for example, sodium or potassiummethoxide or butoxide, and the phenates. The use of the above and othercatalysts is well known to the chemistry of the isocyanates, andreference is again made to the work of Saunders, supra, pp. 94 et seq.

The amount of catalyst typically comprises from 0.01 to 10% of the totalweight of the (A)+(B) mixture.

In another embodiment, it has also been found that, in place of theforegoing catalysts, or alternatively in conjunction therewith,excellent results may be obtained by performing the subject reaction inthe presence of a vinyl pyridine, optionally substituted, for example,2-vinyl or 4-vinylpyridine, or 5-methyl-2-vinylpyridine.

If a vinylpyridine be employed, it has also been found that it ispossible to very greatly exceed the amounts indicated above for thecatalyst. Practically, it is possible to use up to 30% by weight ofvinylpyridine with respect to the total weight of the (A)+(B)composition.

All of the foregoing outlines the essential elements necessary to obtainpolymers within the ambit of the invention. As a general rule, onemerely formulates any composition containing these elements, i.e., thepolyisocyanate, the imide, and the catalyst. The composition isgenerally formulated in the form of a homogeneous solution with aviscosity of the order of 1 to 100 poises at a temperature between 30°and 100° C. In this form, since the reaction has not yet taken place,the viscosity of the composition increases very slowly and the user hassufficient time to carefully apply the composition, for example, as amolding resin, impregnating varnish, coating or adhesive composition formetals, films, particularly polyester films, plastics, and the like.

In order to extend the storage stability or shelf life of thecomposition (pot-life) even longer, additives known for this purposelogically may be added, in particular, the polymerization inhibitorssuch as chlorinated solvents, tetrachlorobenzoquinone, for example, inquantities up to 5% of the composition (by weight).

Excessively rapid reactions may also be prevented by usingpolyisocyanates with all or part of the NCO groups blocked; the use ofsuch blocking agents too is well known to the art and by way ofillustration the following compounds are mentioned as representativeblocking agents: phenolic compounds (phenol, cresol, xylol,hydroxybenzoic acid), the lactams (ε-caprolactam, γ-butyrolactam), theβ-dicarbonyls (diethyl or dimethylmalonate, ethylacetoacetyl), theamides (acrylamide, acetamide), carbonates, imines, mercaptans, oximes,and the like. The blocking reaction may take place in the presence of anorganostannic compound.

The use of blocking agents is well known in the chemistry of isocyanatesand reference is made, for example, to the article by Zeno Wicksentitled "Blocked Isocyanates", published in Progress in OrganicCoatings, 1975, pp. 73-99.

The temperature of the reaction between the polyisocyanate and the imidedepends on the nature of the reagents involved, the optional presence ofpolymerization inhibitors, the potential presence of blockedisocyanates, and the nature and the amount of the catalyst. As a generalrule, the reaction is initiated by heating to a temperature equal atleast to 100° C., a temperature between 120° and 250° C. typically beingemployed.

As indicated above, the compositions comprising the polyisocyanate, theimide and the catalyst, may be utilized as such as molding resins,varnishes, and the like. In order to modify certain characteristics ofthe resin or of the finished product, it is possible to incorporate inthe subject compositions comonomers susceptible either tocopolymerization with the imides (B) or condensation with theisocyanates (A).

Comonomers capable of copolymerization with the imides are, for example,olefinically unsaturated monomers of the maleic, vinyl, acrylic, allylictypes. Exemplary of such monomers, there are noted N-vinyl-pyrrolidone,acrylamide, diallyl phthalate, styrene, triallyl isocyanurate, triallylcyanurate; comonomers that are reactive with respect to isocyanates are,for example, hydroxyl compounds, such as the polyols or epoxy resins.

The reaction of an isocyanate with an epoxy resin is itself known andsuch a resin may be selected from among conventional epoxy resins whichcontain, per molecule, at least two 1,2-epoxy groups. These resins maybe prepared by reaction of epichlorohydrin with polyols, such asglycerol, trimethylolpropane, butanediol, pentaerythritol. Glycidylphenol ethers, such as bis(4-hydroxyphenyl)-2,2-propane,bis(4-hydroxyphenyl)methane, resorcinol, hydroquinone, pyrocatechol,phloroglucinol, 4,4'-dihydroxydiphenyl and condensation products of thephenol/aldehyde type, may also be used. Products of the reaction ofepichlorohydrin with primary or secondary amines, such as bis(4-aminomethylphenyl)methane or bis(4-aminophenyl)sulfone; also thealiphatic or alicyclic polyepoxides resulting from epoxidation by meansof the peracids or hydroperoxides of corresponding unsaturated parentcompounds, too may be utilized.

The amount of the moderator or comonomer as defined above may varywithin broad limits, with the proviso, however, that the ratio r(previously defined) remains within the limits indicated. It is readilyunderstood that if one, for example, employed a large amount ofpolyisocyanates (r=15), a portion of the NCO groups may be "consumed" byemploying a polyol, provided that a sufficient number of NCO groupsremains, so that the ratio r is at least 0.3. The same proviso applies,with the necessary changes, to the comonomers susceptible tocopolymerization with the unsaturated imide.

As above indicated, compositions consisting of a simple mixture of theseveral components can be used per se as molding resins, varnishes, etc.The reaction takes place under those temperature conditions previouslydefined, in the mold, for example, or on a coating, impregnation, oradhesive support.

It is advantageous to bake the resultant shaped articles, for example,at temperatures between 180° and 300° C., to obtain articles, adhesivelybonded joints or coatings which are highly resistant to temperature andsolvents. Thus, polyester films coated with these polymers can withstandvery long periods of exposure without damage at temperatures between155° and 185° C.

It is possible, from polymers according to the invention and films, inparticular polyester films, to produce materials which consist of apolyester film coated on each face with a layer of subject polymer. Itis also possible to produce multilayer materials or laminates,specifically complex films consisting alternately of a layer of apolymer according to the invention, polyester film, polymer layer,polyester film, polymer layer. Such film combinations, to which thepresence of polymer layers according to the invention (including thelayer between the two polyester films) lend a remarkable thermalstability, combine such thermal stability with other desirableproperties, in particular mechanical properties, required for certainapplication. Varnished articles, adhesives, articles or composite filmsproduced from polymers according to the invention thus constitutematerials of choice in such industries as the electric and electronicindustries, and the aeronautical and aerospace industries; also forplate insulation, and the coating or winding of electrical conductors.The composite films described above are especially well adapted for theprotection of electrical conductors in the design of electric motors:the films may be used for insulating the motor slots, the bottom of themotor slot and its closure.

In order to further illustrate the present invention and the advantagesthereof, the following specific examples are given, it being understoodthat the same are intended only as illustrative and in nowiselimitative.

EXAMPLE 1

In a reactor equipped with an agitator and heated to 120°, 25 g ofN,N'-4,4'-diphenylmethanebismaleimide were dissolved in 65 g of apolyisocyanate composed of 57% by weight ofdiphenylmethane-4,4'-diisocyanate, 25% by weight of triphenyldimethylene triisocyanate and 18% by weight of tetraphenyl trimethylenetetraisocyanate. (Polyisocyanate titer of 0.728 NCO/100 g).

The solution was subsequently degassed and 10 g 4-vinylpyridine wasadded thereto.

This liquid resin which had a viscosity of 2 poises at 75° was pouredinto a rectangular mold preheated to 150° C. The assembly was maintainedfor 4 h at 150° C., then at 200° C. for 24 hours.

The resulting molded shaped article displayed the properties describedin Table I.

EXAMPLE 2

The experiment of Example 1 was repeated, but using the polyisocyanate,the bismaleimide and the 4-vinylpyridine in the proportions of 75/20/5by weight. The viscosity of the resin was 2 poises at 65° C.

The properties of the resulting molded shaped article are compiled inTable I.

EXAMPLE 3

Example 1 was repeated, but using the polycyanate, the bismaleimide andthe 4-vinylpyridine in the proportions of 50/40/10 by weight. Theviscosity of the resin was 10 poises at 95° C.

The properties of the resulting molded cast article are compiled inTable I.

                  TABLE I                                                         ______________________________________                                                     EXAM-     EXAM-                                                  PROPERTIES   PLE 1     PLE 2     EXAMPLE 3                                    ______________________________________                                        Rf at 25° C. kg/mm.sup.2                                                            12.6      12.3      12.5                                         Rf at 200° C. kg/mm.sup.2                                                           7.4       6.5       8.5                                          Mf at 25° C. kg/mm.sup.2                                                            280       291       288                                          Mf at 200° C. kg/mm.sup.2                                                           254       214       255                                          Rc in j/cm.sup.3                                                                           0.54      0.50      0.70                                         ______________________________________                                         Rf: Bending strength at rupture (ASTM Standard D 790.63)                      Mf: Bending modulus at rupture (ASTM Standard D 790.63)                       Rc: Impact strength (Izod impact test/unnotched/on microspecimen, N.F. PT     51.017).                                                                 

EXAMPLE 4

At 120° C., under agitation, 35 g N,N'-4,4'-diphenylmethane bismaleimidewas dissolved in 65 g polyisocyanate, as described in Example 1.

The temperature was then lowered to 70° C. and 2 g2,4,6-tris(dimethylaminomethyl)phenol were added.

The solution was degassed and poured into a parallelepiped moldpreheated to 150° C. The assembly was maintained for 5 h at 150° C. thenat 200° C. for 20 h.

The molded shaped article had a bending strength at rupture at 25° C. of13.8 kg/mm².

EXAMPLE 5

Example was repeated, but replacing the bismaleimide withN-phenylmaleimide.

The bending strength at rupture at 25° C. of the molded object was 14.1kg/mm².

EXAMPLE 6

Example 4 was repeated, but employing a polyisocyanate/bismaleimidoratio of 75/25.

Bending strength at rupture at 25° C. of the molded object was 10.3.

EXAMPLE 7

At 120° C., under stirring, 30 g N,N'-4,4'-diphenylmethane bismaleimidewere dissolved in 50 g of a polyisocyanate prepolymer obtained by thereaction of 4,4'-diisocyanate diphenylmethane with a butanediolpolyadipate (40 mole%) and ethylene glycol (60 mole %) of molecularweight 2000, with a NCO/OH=5. (The prepolymer titer was 0.228 NCO/100 gand had a viscosity of 1400 poises at 25° C.)

Thereafter, 20 g of the polyisocyanate described in Example 1 wereadded, followed by cooling to 80° C., prior to addition of 10 g4-vinylpyridine.

The viscosity of the solution was 80 poises at 70° C.

With the aid of a ladle heated to and maintained at 70° C., a polyesterfilm (polyterephthalate of ethylene glycol) having a thickness of 175μ,was coated with the liquid resin prepared as above. After 3 mn in afurnace at 175° C., the coating was hardened and displayed goodflexibility and adherence to the film support.

Elongation was 125% and tensile strength 17.5 kg/mm² (coated film).

EXAMPLE 8

Example 7 was repeated, but 10 g N-vinyl-2-pyrrolidone were added. Theviscosity of the resin was 60 poises at 60° C.

The polyester film was coated under the conditions described in Example7, resulting in a transparent, homogeneous, flexible coating with goodadherence to the film support.

EXAMPLE 9

A solution was prepared by dissolving at 120° C., 30 gN,N'-4,4'-diphenylmethane-bismaleimide in 50 g of the prepolymerdescribed in Example 7 and 10 g of the polyisocyanate described inExample 1.

Subsequently, 20 g m-cresol were added as a blocking agent for theisocyanates, and the solution was agitated for 1 h prior to introducing10 g N-vinyl-2-pyrrolidone and 0.25 g of the catalyst used in Example 4.

The resin was placed in a temperature controlled vessel at 70° C.(viscosity was 10 poises at this temperature); a polyester film waspassed through the vessel, which was then dried between two cylindricalrolls upon emerging from the vessel, and before being passed into afurnace maintained at 160° C.

The coating deposited on the polyester film of 175μ thickness, was 15μthick on each face surface, transparent, had a yellow tint, and washomogeneous, flexible and adherent to the polyester support.

Specimens of the coated film were subjected to aging at 185° and 200° C.Clear improvement in resistance to elevated temperatures of thepolyester film was observed, as shown by the results set forth below(the control film received no coating of any kind).

                                      TABLE 2                                     __________________________________________________________________________                  Initial                                                         Duration of aging                                                                           values                                                                              100 h 250 h 500 h 700 h                                                                              900 h                              treatment in hours                                                                          A %                                                                              R  A %                                                                              R  A %                                                                              R  A %                                                                              R  A %                                                                              R A %                                                                              R                               __________________________________________________________________________            control film                                                                        126                                                                              17.3                                                                              22.5                                                                            11.6                                                                             0.8                                                                              2.2                                                                              0.2                                                                              0.5                                                                              0    0                                  at 185° C.                                                                     coated film                                                                         122                                                                              17.3     11 15 3  10.5                                                                             2.3                                                                              8.3                                                                             1.9                                                                              7                                       control film                                                                        126                                                                              17.3                                                                              1 3.5                                                                              0.5                                                                              1.4                                                                              0  0                                          at 200° C.                                                                     coated film                                                                         122                                                                              17.3                                                                              12.4                                                                            11.8                                                                             3.3                                                                              10.5                                                                             2.5                                                                              9.7                                                                              2  7.9                                                                             1.8                                                                              6.7                             __________________________________________________________________________     A: Elongation in %                                                            R: Tensile strength at rupture at 25° in kg/mm.sup.2              

EXAMPLE 10

A mixture was prepared at 80° C. under agitation, of 50 g of theprepolymer described in Example 7, 20 g toluene diisocyanate and 50 gm-cresol, in the presence of 1 g tin dibutyldilaurate. After 1 h at 80°C., 8 g butanediol-1,4, 2 g dimethylolpropane, and 30 g4,4'-bismaleimidodiphenylmethane were added and the mixture homogenizedat 100° C. until the bismaleimide was completely dissolved.

The liquid resin was then cooled to 70° C. (viscosity then was 35poises) and 1 g of a solution of 30% potassium acetate in diethyleneglycol and 1 g of tin dibutyldilaurate were introduced.

From this resin, a film was prepared by depositing a thin layer thereofon a glass plate and hardening same at 180° C. for 5 mn. The filmobtained had good flexibility, and was inert to solvents such as xylene,carbon tetrachloride, dimethylformamide,dichloro-1,1-trifluoro-1,1,1-ethane (Freon 113)/100 h in the solvent at25° C., except for the Freon: 4° C./.

EXAMPLE 11

The preceding example was repeated, but employing 40 g caprolactam inplace of the m-cresol. At 70° C. the viscosity of the resin was 70poises.

The film obtained had characteristics identical to those of the filmprepared in said preceding example.

EXAMPLE 12

Example 10 was repeated, but using as the blocking agent (replacingm-cresol) acrylamide and dimethylmalonate.

These products were used in stoichiometric quantities with respect tothe polyisocyanate. The viscosity of the resin at 70° C. was,respectively: 100 poises with the acrylamide, 2 poises with thedimethylmalonate.

EXAMPLE 13

Example 10 was repeated, but using as the macrodiisocyanate prepolymer apolyoxypropylene with NCO terminal groups, having a viscosity of 148poises at 25° C., and with a titer 0.240 NCO per 100 g.

The isocyanate used to prepare the macrodiisocyanate wasbis(4-isocyanatophenyl)methane.

The film obtained by deposition on a glass plate was highly flexible.

EXAMPLE 14

The resin prepared in Example 11 was deposited in a thin layer on apolyimide film (polypyromellitimide of diaminodiphenylether).

Hardening took place at 200° C. for 5 mn, and very good adherence of thecoating to the polyimide film was observed.

EXAMPLE 15

Into a reactor placed into a 70° C., 300 g4,4'-diisocyanatodiphenylmethane, 200 g caprolactam and 1 g tindibutyldilaurate were introduced. The mixture was heated to 100° C. withagitation in 1 h, then 500 g 4,4'-bismaleimido-diphenylmethane wereadded. The temperature was increased to 140° C. until the bismaleimidewas completely dissolved, then 10 cm³ of a solution of 30% potassiumacetate in diethylene glycol were added.

The resin was then cooled on a pan to ambient temperature, and thenceground.

The powder obtained softens around 80° C. and was used to coat aluminumplates preheated to 200° C., simply by sprinkling the powder with theaid of a sieve.

The fused resin was immediately distributed. Following baking at 200° C.for 8 h, it was found that the coating adhered firmly to the support anddid not exhibit cracking or swelling.

EXAMPLE 16

This example illustrates the preparation of a composite film comprising:a layer of the polymer/polyester film/polymer layer/polyesterfilm/polymer layer.

The polymer was prepared as follows:

A mixture was made, at 80° C., under agitation, of:

60 g of the polyisocyanate prepolymer used in Example 7;

20 g toluene diisocyanate;

40 g ε-caprolactam; and

0.11 g tin dibutyldilaurate.

The mixture was maintained at 80° C. under agitation for 1 h, then 30 gN,N'4,4'-diphenylmethane bismaleimide were introduced, and thetemperature next raised to 130° C. Following the dissolution of thebismaleimide, 14 g butanediol-1,4 and 2 g trimethylolpropane wereintroduced in the reactor, the temperature lowered to 85° C. and 0.16 gtin dibutyldilaurate, 1.6 g of a solution of potassium acetate (0.48 g)in diethylene glycol, were added.

The resin obtained had a viscosity of approximately 30 poises at 80° C.

This resin was placed into an impregnating vat with double walls,controlled at a temperature of 90°-95° C. with circulating oil; theheating of the resin produced a viscosity of approximately 5 poises.

Two polyester films (ethylene glycol polyterephthalate) were used, thethickness of each was 125μ.

The two polyester films (hereafter Film A and Film B) were coated asfollows: the two films, A and B, were treated with a flow discharge(using the machine, "Effluveur LEPEL", Model HF SG2) in order to raisethe surface tension to approximately 60 dynes/cm), rid of staticelectricity (using a Deselectriseur Regma, Model WD 120) and cleaned ofdust (by aspiration).

The films were then conveyed through the bath containing the resin, onseparate rolls, to permit the coating of each film on both faces andthence superimposed; subsequently, the composite assembly was passedthrough heated cylindrical bars. The gap between the bars controlled thetotal thickness of the composite film. The gap used in this example was270μ. The composite film was then conveyed to and through a furnaceheated to 150° C., remaining in the furnace for 7 mn.

Using the resin described above and following the mode of operation setforth, a composite film comprising the two polyester films and thevarious layers of resin was prepared, the total thickness of thecomposite film being approximately 300μ, the thickness of the resinlayers being approximately 10-15μ for the external layers andapproximately 20-30μ for the internal layers.

While the invention has been described and illustrated with reference tocertain preferred embodiments thereof, those skilled in the art willappreciate that various changes, modifications and substitutions thereincan be made without departing from the spirit of the invention. It isintended, therefore, that the invention be limited only by the scope ofthe claims which follow.

What is claimed is:
 1. A composition of matter comprising (A) at leastone organic polyisocyanate, (B) at least one unsaturated imide selectedfrom the group consisting of:(i) a monoimide of the formula: ##STR15##wherein D represents ##STR16## in which Y is H, CH₃ or Cl, and Z iseither 0, 1 or 2, and R₁ is hydrogen or a monovalent aliphatic,cycloaliphatic or aromatic hydrocarbon radical containing up to 20carbon atoms; and (ii) a polyimide of the formula: ##STR17## wherein Dis as above, n is a number ranging from 2 to 5 and R₂ is a radicalhaving the valence n, such R₂ radical being selected from the groupconsisting of a wholly hydrocarbon radical, a heteroatom interruptedhydrocarbon radical, a heterocycle radical and a heterocycle containinghydrocarbon radical and wherein said composition the ratio r of totalisocyanate functions in the polyisocyanate (A) to total polymerizabledouble bonds in the unsaturated imide (B) is in the range of from 0.3 to15, and (C) an additional comonomer which is an olefinically unsaturatedcomonomer copolymerizable with the unsaturated imide (B).
 2. An imidopolymer, comprising the polyaddition product of the composition ofmatter as defined by claim
 1. 3. The composition of matter as defined byclaim 1, wherein the polyisocyanate is a monomeric polyisocyanate of theformula:

    R.sub.3 --NCO).sub.m                                       [III]

in which m is a number of from 2 to 5, and R₃ represents a radical withthe valence m and is an aliphatic, cycloaliphatic or aromatic radicalhaving up to 50 carbon atoms, said R₃ radical being selected from thegroup consisting of a wholly hydrocarbon radical, a heteroatominterrupted hydrocarbon radical, a heterocycle radical, and aheterocycle containing hydrocarbon radical.
 4. The composition of matteras defined in claim 3, wherein the number m is either 2 or
 3. 5. Thecomposition of matter as defined by claim 3, wherein R₃ is a straight orbranched chain aliphatic radical having up to 12 carbon atoms, a C₁ -C₁₂alkylene radical, a cycloaliphatic radical having 5 to 6 ring carbonatoms, a monocyclic or fused bicyclic aromatic radical, a ##STR18##radical where p is 1, 2 or 3, a polycyclic aromatic radical as definedabove, the individual rings or which being either fused or linked by asimple valence bond, or linked by an atom or bridge selected from thegroup consisting of --O--, --S--, --SO₂ -- or an alkylene radicalcontaining 1 to 4 carbon atoms, or further wherein the various aromaticnuclei are substituted with one or more halogen atoms, or with one ormore alkyl radicals having 1 to 4 carbon atoms, or with a methoxy group.6. The composition of matter as defined by claim 3, wherein thepolyisocyanate is selected from the group consisting oftoluene-2,4-diisocyanate, mixtures of toluene-2,4-diisocyanate andtoluene-2,6-diisocyanate, bis(4-isocyanatophenyl)methane, paraphenylenediisocyanate, metaphenylene diisocyanate, 1,5-diisocyanatonaphthalene,tris(4-isocyanatophenyl)methane, 2,4-diisocyanato-chlorobenzene,bis(4-isocyanatophenyl)ether, 1,6-diisocyanatohexane,3,3'-dimethyl-4,4'-diisocyanato-biphenyl,bis(4-isocyanatocyclohexyl)methane,bis(3-methyl-4-isocyanatophenyl)methane, bis(4-isocyanatophenyl)propane,4,4'-diisocyanato-3,3'-dichloro diphenyl, and polyisocyanates of theformula: ##STR19## where w is a number ranging from 0.1 to
 4. 7. Thecomposition of matter as defined by claim 1, wherein the component (A)further comprises up to 30% of a monoisocyanate of the formula:

    G--NCO                                                     [VII]

wherein the symbol G is a substituted or unsubstituted, saturated orunsaturated, linear or branched chain aliphatic radical, having up to 8carbon atoms, a C₁ -C₈ alkyl radical, a cycloalkyl radical with 5 or 6carbon atoms, a phenyl radical, an alkylphenyl or phenylalkyl radicalwith up to 12 carbon atoms, said substituents being one or two chlorineatoms or a methoxy group.
 8. The composition of matter as defined byclaim 1, wherein the unsaturated imide has the formula I, and R₁represents a substituted or unsubstituted, linear or branched chainalkyl or alkenyl radical containing up to 20 carbon atoms, a cycloalkylradical containing 5 or 6 carbon atoms in the ring, a mono- or bicyclicaryl radical or aralkyl radical containing up to 20 carbon atoms,##STR20## a monovalent radical selected from the group consisting of aphenyl radical and at least one phenylene radical joined together by asimple valence bond or by an atom or an inert bridge selected from thegroup --O--, --S--, an alkylene radical with 1 to 3 carbon atoms,--CO--, --SO₂ --, NR₄ --, --N═N--, --CONH--, --COO--, where R₄represents H, CH₃, phenyl or cyclohexyl, said substitutents beingselected from the group F, Cl, CH₃, OCH₃, OC₂ H₅, OH, NO₂, --COOH,--NHCOCH₃, and ##STR21##
 9. The composition of matter as defined byclaim 1, wherein the unsaturated imide is selected from the groupconsisting of maleimide, N-phenylmaleimide, N-methylphenylmaleimide,N-phenylchloromaleimide, N-p-chlorophenylmaleimide,N-p-methoxyphenylmaleimide, N-p-methylphenylmaleimide,N-p-nitrophenylmaleimide, N-p-phenoxyphenylmaleimide,N-p-phenylcarbonylphenylmaleimide,maleimido-1-acetoxysuccinimido-4-benzene,maleimido-4-acetoxysuccinimido-4'-diphenylmethane,maleimido-4-acetoxysuccinimido-4'-diphenylether,maleimido-4-acetamido-4-diphenylether, maleimido-2-acetamido-6 pyridine,maleimido-4-acetamido-4'-diphenylmethane, N-methylmaleimide,N-ethylmaleimide, N-vinylmaleimide, N-allylmaleimide,N-cyclohexylmaleimide, N-decylmaleimide.
 10. The composition of matteras defined by claim 1, wherein the unsaturated imide has the formula II,and R₂ is an alkylene radical, linear or branched, containing up to 13carbon atoms; a cyclohexylene or cyclopentylene radical; a phenylene ornaphthylene radical; ##STR22## where s is equal to 1, 2 or 3; a radicalcontaining two phenylene or cyclohexylene radicals joined to each otherby a simple valence bond or by a linking atom or inert bridge selectedfrom the group consisting of --O--, --S--, an alkylene group having 1 to3 carbon atoms, ##STR23## where R₅ represents a hydrogen atom, an alkylradical having 1 to 4 carbon atoms, phenyl or cyclohexyl and Xrepresents an alkylene radical having up to 13 carbon atoms.
 11. Thecomposition of matter as defined by claim 1 wherein the unsaturatedimide is selected from the group consisting ofN,N'-ethylene-bis-maleimide, N,N'-metaphenylene-bis-maleimide,N,N'-hexamethylene-bis-maleimide, N,N'-para-phenylene-bis-maleimide,N,N'-4,4'-biphenylene-bis-maleimide,N,N'-4,4'-diphenylmethane-bis-maleimide,N,N'-4,4'-diphenyl-methane-bis-tetrahydrophthalimide,N,N'-4,4'-diphenylether-bis-maleimide,N,N'-4,4'-diphenylthio-bis-maleimide,N,N'-4,4'-diphenylsulfone-bis-maleimide,N,N'-4,4'-dicyclohexylmethane-bis-maleimide, N,N'-,'-4,4'-dimethylenecyclohexane-bis-maleimide, N,N'-paraxylylene-bis-maleimide,N,N'-4,4'-diphenyl-1,1-cyclohexane-bis-maleimide,N,N'-4,4'-diphenylmethane-bis-citraconimide,N,N'-4,4'-diphenylether-bis-endometylene tetrahydrophthalimide,N,N'-4,4'-diphenylmethane-bis-chloro-maleimide,N,N'-4,4'-diphenyl-1,1-propane-bis-maleimide,N,N'-4,4'-triphenyl-1,1,1-ethane-bis-maleimide,N,N'-4,4'-triphenylmethane-bis-maleimide,N,N'-3,5-triazole-1,2,4-bis-maleimide,N,N'-dodecamethylene-bis-maleimide,N,N'-trimethyl-2,2,4-hexymethylene-bis-maleimide,bis(maleimido-2-ethoxy)-1,2-ethane,bis(maleimido-3-propoxy)-1,3-propane,N,N'-4,4'-benzophenone-bis-maleimide,N,N'-pyridinediyl-2,6-bis-maleimide, N,N'-naphthylene-1,5-bis-maleimide,N,N'-cyclohexylene-1,4-bis-maleimide,N,N'-methyl-5-phenylene-1,3-bis-maleimide, andN,N'-methoxy-5-phenylene-1,3-bis-maleimide.
 12. The composition ofmatter as defined by claim 1, wherein the unsaturated imide has thestructural formula: ##STR24## wherein y is number from 0.1 to 4, and R₆is a divalent hydrocarbon radical having 1 to 8 carbon atoms.
 13. Thecomposition of matter as defined by claim 1 wherein the ratio r is inthe range of from 0.5 to
 10. 14. The composition of matter as defined byclaim 1 further comprising a catalytic amount of an isocyanatepolymerization catalyst.
 15. The composition of matter as defined byclaim 1, wherein the polyisocyanate is a polyisocyanate prepolymerselected from the group consisting of those of the formulae: ##STR25##wherein Σ₁ comprises a divalent organic radical derived from a polymercontaining at least two reactive hydroxyl or amino groups, saidprepolymer resulting from the reaction of a molar excess of diisocyanateof the formula OCN--R₃ --NCO with said reactive hydroxyl or aminogroup-containing polymer.